1. Field of the Invention
The present invention relates to an image pickup apparatus capable of distributing picked up images through a network and to an image distributing method used in the apparatus. Particularly, the present invention relates to an image pickup apparatus and an image distributing method capable of obtaining an image of an encoding method suitable for an environment, such as a communication speed of a network and a storage capacity.
2. Description of the Related Art
In a known method for guarding a megastructure, several hundreds of monitoring cameras are set in a guard area, video images picked up by those cameras are displayed on several tens of monitors in a time-division manner, and observers observe these images on the monitors in real time. In recent years, an IP camera (Internet protocol camera, also called a network camera) connected to a network through Ethernet® or the like has been used as a monitoring camera. The IP camera has a characteristic of broadcasting video images to a plurality of client monitoring terminals, such as PCs (personal computers) so that the images can be monitored. In addition, the IP camera has an advantage of enabling the client monitoring terminals to control the IP camera, for example, control pan/tilt or zoom or select a preset position.
In such a monitoring camera system using a network, the cost increases as the scale of the system configuration becomes larger. In order to suppress the increase in the cost, the following system is suggested. That is, a moving-object sensor to detect an abnormal motion in a monitoring area is provided in each monitoring camera, and only signals output from monitoring cameras selected in accordance with a detection output of the moving-object sensor are transmitted to a signal recording/playback unit (e.g., see Patent Document 1: Japanese Unexamined Patent Application Publication No. 07-212748 (paragraphs [0027] to [0040] and FIG. 6)). Accordingly, only signals output from monitoring cameras that are selected in accordance with a detection output of the moving-object sensor can be transmitted to a monitor. With this configuration, an observer need not monitor the monitor in real time, so that a monitoring operation can be efficiently performed.